US8560263B2 - Power distribution network estimation device - Google Patents
Power distribution network estimation device Download PDFInfo
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- US8560263B2 US8560263B2 US13/029,392 US201113029392A US8560263B2 US 8560263 B2 US8560263 B2 US 8560263B2 US 201113029392 A US201113029392 A US 201113029392A US 8560263 B2 US8560263 B2 US 8560263B2
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- electric power
- value
- supply end
- sensors
- resistance value
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00006—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment
- H02J13/00007—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network characterised by information or instructions transport means between the monitoring, controlling or managing units and monitored, controlled or operated power network element or electrical equipment using the power network as support for the transmission
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J13/00—Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
- H02J13/00032—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for
- H02J13/00034—Systems characterised by the controlled or operated power network elements or equipment, the power network elements or equipment not otherwise provided for the elements or equipment being or involving an electric power substation
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S40/00—Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them
- Y04S40/12—Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them characterised by data transport means between the monitoring, controlling or managing units and monitored, controlled or operated electrical equipment
- Y04S40/121—Systems for electrical power generation, transmission, distribution or end-user application management characterised by the use of communication or information technologies, or communication or information technology specific aspects supporting them characterised by data transport means between the monitoring, controlling or managing units and monitored, controlled or operated electrical equipment using the power network as support for the transmission
Definitions
- the embodiments discussed herein are related to a power distribution network estimation device.
- a method may be cited in which, using electric-power sensors provided between outlets provided in a power distribution network and all loads connected to the outlets, the amounts of electric currents flowing into the loads and the voltages at positions to which loads are connected are measured, and hence total electric power consumption in the facility is obtained on the basis of the electric power measurement results for all loads.
- a method or the like has been proposed in which, by using electric-power sensors, the voltage values at positions to which loads are connected are measured, and total electric power consumption in a facility is estimated. Focusing on a system included in a power distribution network, the amount of a voltage drop and the conductor resistance value of an electric wire, which lead up to a position to which an electric-power sensor is connected, are measured. Accordingly, the amounts of electric currents flowing into the loads connected to the system are estimated, and electric power consumption is estimated on the basis of the estimated amounts of currents. After that, by summing the estimated amounts of electric power consumption in individual systems for all systems, electric power consumption in the entire facility is estimated.
- the term “system” means each of circuits included in a power distribution network used for receiving generated electric power from a power transmission network and distributing the electric power, and means each of circuits branching from a trunk line.
- FIG. 1 is a schematic view illustrating a power distribution network that distributes electric power, received from a power transmission network, to loads connected to a system 1 and a system 2 .
- a transformer T 1 is, for example, provided on a distribution board, the primary side input of the transformer T 1 is connected to the power transmission network, and a consumer-side power distribution network is connected to the secondary side output thereof.
- Resistances r 1 to r 8 indicate the conductor resistances of circuit wiring lines.
- Branching in FIG. 1 indicates the branching of a trunk line, and corresponds to, for example, a branch circuit such as a distribution board when house wiring is assumed.
- an outlet C 1 is provided in the system 1 , and a load F 1 is connected to the outlet C 1 through an electric-power sensor Se 1 .
- An outlet C 2 and an outlet C 3 are provided in the system 2 , a load F 2 is connected to the outlet C 2 through an electric-power sensor Se 2 , and a load F 3 is connected to the outlet C 3 through an electric-power sensor Se 3 . Focusing on the system 2 included in the power distribution network, the amount of a voltage drop and the conductor resistance value of an electric wire, which lead from a position to which the electric-power sensor Se 2 is connected up to a position to which the electric-power sensor Se 3 is connected, are measured.
- the amounts of currents flowing into all loads connected to the system 2 are estimated, and electric power consumption is estimated on the basis of the estimated amounts of currents. After that, with respect to the system 1 , electric power consumption is also estimated, and, by summing the estimated amounts of electric power consumption for all systems, total electric power consumption in the facility is estimated.
- an estimation device that estimates a positional relationship between a plurality of loads in a power distribution network, the loads being individually connected through a plurality of sensors to a plurality of electric power-supply ends provided in the power distribution network includes a communication unit configured to change a resistance value located between each of the electric power-supply ends and a ground terminal of each of sensors and measure a voltage value produced between each of the electric power-supply ends and the ground terminal, by communicating with the plural sensors; and a determination unit configured to select two sensors from among the sensors connected to the power distribution network, acquire voltage values from the two selected sensors through the communication unit, acquire voltage values from the two selected sensors after a resistance value of one of the two sensors that has a higher acquired voltage value is changed, calculate, with respect to each of the two sensors, a ratio between voltage values acquired before and after the resistance value is changed, and determine that the two sensors are connected to a branch circuit in a same system in the power distribution network, when the ratio is within a specified range with respect to each of the two sensors
- FIG. 1 is a diagram illustrating a power distribution network of the related art
- FIG. 2 is a diagram illustrating an embodiment of a system in which a power distribution network estimation device and sensors;
- FIG. 3A is a diagram illustrating an embodiment of a sensor that includes a switch
- FIG. 3B is a diagram illustrating an embodiment of a sensor that includes a switch and a variable resistance
- FIG. 4 is a diagram illustrating an embodiment of the power distribution network estimation device
- FIG. 5 is a diagram illustrating an embodiment for estimating a system in a power distribution network (a positional relationship is unspecified);
- FIG. 6 is a diagram illustrating an embodiment for estimating a system in a power distribution network
- FIG. 7 is a diagram illustrating an embodiment for estimating a system in a power distribution network
- FIG. 8 is a substantially equivalent circuit illustrating an embodiment for estimating a positional relationship between sensors
- FIG. 9 is a substantially equivalent circuit illustrating an embodiment for estimating a positional relationship between sensors
- FIG. 10 is a substantially equivalent circuit illustrating an embodiment for estimating a positional relationship between sensors
- FIG. 11 is a diagram illustrating embodiments of a sensor and a recording unit
- FIG. 12 is a flowchart illustrating an embodiment of an operation performed in a voltage value acquisition unit
- FIG. 13 is a flowchart illustrating an embodiment of an operation performed in a resistance value change unit
- FIG. 14 is a flowchart illustrating an embodiment of an operation performed in a measurement synchronization unit
- FIGS. 15A to 15C are diagrams illustrating embodiments of structures of databases recorded in the recording unit in the sensor
- FIG. 16 is a diagram illustrating an embodiment of a system determination unit
- FIG. 17 is a diagram illustrating an embodiment of an operation performed in a voltage measurement request unit
- FIG. 18 is a diagram illustrating an embodiment of an operation performed in a resistance change request unit
- FIG. 19 is a diagram illustrating an embodiment of an operation performed in a measurement synchronization request unit
- FIG. 20 is a flowchart illustrating an embodiment of an operation for determining a positional relationship between sensors
- FIG. 21 is a flowchart illustrating an embodiment of an operation for determining a positional relationship between sensors
- FIG. 22 is a flowchart illustrating an embodiment of an operation for estimating a positional relationship between all sensors in a power distribution network
- FIGS. 23A to 23D are diagrams illustrating embodiments of structures of databases recorded in a recording unit in the power distribution network estimation device
- FIG. 24 is a flowchart illustrating an embodiment of an operation performed in the measurement synchronization request unit when a synchronization operation is periodically performed
- FIG. 25A is a substantially equivalent circuit illustrating an embodiment of loads connected to a same system in a power distribution network
- FIG. 25B is a diagram illustrating an embodiment of loads connected to a same system in a power distribution network
- FIG. 26 is a diagram illustrating an embodiment of a fitting operation
- FIG. 27 is a diagram illustrating a method used for estimating the presence or absence of a load between electric power-supply ends
- FIG. 28 is a diagram illustrating embodiments of sensors and loads connected to a same system in a power distribution network
- FIG. 29 is a diagram illustrating embodiments of a load presence/absence determination unit, an electric power consumption calculation unit, and a recording unit;
- FIG. 30 is a flowchart illustrating embodiments of operations performed in load presence/absence determination and electric power consumption calculation
- FIG. 31 is a flowchart illustrating embodiments of operations performed in the load presence/absence determination and the electric power consumption calculation
- FIG. 32A to FIG. 32E are diagrams illustrating embodiments of structures of databases recorded in the recording unit in the power distribution network estimation device
- FIG. 33 is a diagram illustrating an embodiment in which there is a load between electric power-supply ends
- FIG. 34 is a flowchart illustrating an embodiment of an operation for obtaining a slope A and an intercept B of a linear function
- FIG. 35 is a diagram illustrating an embodiment in which electric power consumption of a portion subsequent to an electric power-supply end near a distribution board is measured
- FIG. 36 is a diagram illustrating a circuit configuration when a single-phase two-wire method is used (a sensor is connected);
- FIG. 37 is a diagram illustrating a circuit configuration when a single-phase two-wire method and a three-terminal outlet are used (a sensor is connected);
- FIG. 38 is a diagram illustrating a circuit configuration when a single-phase three-wire method is used (a sensor is connected).
- FIG. 39 is a diagram illustrating an embodiment of a hardware configuration of a computer that can realize a power distribution network estimation device according to the embodiment.
- the estimation of a system in a power distribution network, the estimation of the connection state of a load, and the estimation of electric power consumption are performed using a voltage value that is the measurement result of a load voltage, obtained by a sensor used for measuring the fluctuation of the voltage of the load connected to the power distribution network.
- FIG. 2 is a schematic view illustrating an example of a relationship between sensors and a power distribution network estimation device.
- a power distribution network for distributing electric power, received from a power transmission network, to loads connected to a system 1 and a system 2 is illustrated.
- a transformer T 1 is, for example, provided on a distribution board, the primary side (input) of the transformer T 1 is connected to the power transmission network, and a consumer-side power distribution network is connected to the secondary side (output) thereof.
- Resistances r 1 to r 8 indicate the conductor resistances of circuit wiring lines.
- Branching in FIG. 2 indicates the branching of a trunk line, and corresponds to, for example, a branch circuit such as a distribution board when house wiring is assumed.
- an electric power-supply end (outlet C 1 ) is provided in the system 1
- electric power-supply ends (outlets C 2 and C 3 ) are provided in the system 2 .
- a load F 1 is connected to the outlet C 1 through a sensor SV 1
- a load F 2 is connected to the outlet C 2 through a sensor SV 2
- a load F 3 is connected to the outlet C 3 through a sensor SV 3 .
- the sensors SV 1 , SV 2 , and SV 3 are provided between the outlets C 1 , C 2 , and C 3 used for feeding power from the power distribution network to a plurality of loads and the loads F 1 , F 2 , and F 3 connected to the outlets C 1 , C 2 , and C 3 , respectively.
- the sensors SV 1 , SV 2 , and SV 3 change resistance values between the electric power-supply terminals and ground terminals of the outlets C 1 , C 2 , and C 3 , and measure voltage values between the electric power-supply terminals and ground terminals of the outlets C 1 , C 2 , and C 3 , respectively.
- the sensors SV 1 , SV 2 , and SV 3 transmit to a power distribution network estimation device 1 voltage values that are the results of voltage measurement for the outlets C 1 , C 2 , and C 3 .
- a sensor will be described.
- FIG. 3A is a block diagram illustrating an embodiment of the sensor.
- a sensor 300 includes a switch SW 1 , a voltage measurement unit 301 , a communication unit 302 , a control unit 303 , a recording unit 304 , and connection terminals 305 , 306 , and 307 .
- the switch SW 1 separates a load from the power distribution network in response to an instruction from the control unit 303 .
- the a-side terminal of the switch SW 1 is connected to the a-side terminal of the voltage measurement unit 301 and the connection terminal 305 used for supplying electric power from the power distribution network.
- the b-side terminal of the switch SW 1 is connected to the connection terminal 307 (the input terminal of the load) used for supplying electric power to the load.
- the b-side terminal of the voltage measurement unit 301 is connected to the connection terminal 306 (a ground terminal) of the power distribution network.
- the voltage measurement unit 301 measures a voltage value (a potential difference between the electric power-supply terminal and the ground terminal) produced when the switch SW 1 is opened and a voltage value produced when the switch SW 1 is closed, and transmits the voltage values to the control unit 303 .
- the communication unit 302 communicates with the power distribution network estimation device 1 .
- IP Internet Protocol
- LAN local area network
- PLC power line communications
- the communication unit 302 may use serial communication such as Recommended Standard 232C (RS232C) or the like, or may use Near Field Communication that uses infrared light, Bluetooth (registered trademark), ZigBee (registered trademark), or the like.
- RS232C Recommended Standard 232C
- Near Field Communication that uses infrared light, Bluetooth (registered trademark), ZigBee (registered trademark), or the like.
- the control unit 303 controls individual units using a central processing unit (CPU) or a programmable device.
- the communication unit 302 communicates with the power distribution network estimation device 1 , and receives an instruction for the measurement of a voltage value (measurement start notice) from the power distribution network estimation device 1 , the communication unit 302 transmits the instruction to the control unit 303 .
- the control unit 303 receives the measurement start notice, and outputs an instruction for opening and closing and an instruction for the measurement of a voltage value to the switch SW 1 and the voltage measurement unit 301 , respectively.
- the instruction for the measurement of a voltage value (measurement start notice) is an instruction used for measuring voltage values produced when the switch SW 1 is opened and closed.
- control unit 303 acquires the result of measurement by the voltage measurement unit 301 , and generates and transmits a measurement completion notice, used for giving notice of the completion of the measurement, to the power distribution network estimation device 1 through the communication unit 302 .
- the measurement completion notice includes an identifier assigned to each sensor, the voltage values produced when the switch SW 1 associated with the identifier is opened and closed, and the like.
- the recording unit 304 records therein a program, a table, data, and the like.
- the recording unit 304 is a memory such as a read only memory (ROM), a random access memory (RAM), or the like.
- the recording unit 304 may record therein data such as a parameter value, a variable value, and the like or may be used as a work area. In the example, measurement results and the like are recorded in the recording unit 304 .
- FIG. 3B is a block diagram illustrating an example of a sensor that includes a variable resistance.
- a sensor 308 includes therein a variable resistance RV 1 , and the sensor 308 measures a voltage value produced when the resistance value of the variable resistance RV 1 is changed.
- a fixed resistance RV 1 may be used in place of the variable resistance RV 1 .
- the sensor 308 includes a switch SW 1 , a variable resistance RV 1 , a voltage measurement unit 301 , a communication unit 302 , a control unit 303 , a recording unit 304 , and connection terminals 309 and 310 .
- the b-side terminal of the switch SW 1 is connected to the a-side terminal of the variable resistance RV 1
- the connection terminal 309 is connected to a terminal used for supplying electric power from the power distribution network and an input terminal used for supplying electric power to a load.
- the connection terminal 310 is connected to the ground terminal of the power distribution network.
- the communication unit 311 in the sensor 308 includes the function of the communication unit 302 illustrated in FIG. 3A , and furthermore acquires from the power distribution network estimation device 1 an instruction used for changing the resistance value of the variable resistance RV 1 .
- the communication unit 311 transmits, to the control unit 312 in the sensor 308 , the instruction used for changing the resistance value of the variable resistance RV 1 .
- the control unit 312 in the sensor 308 includes the function of the control unit 303 illustrated in FIG. 3A , and outputs to the variable resistance RV 1 an instruction used for changing the resistance value thereof.
- the sensor 308 is not necessarily connected to the load.
- the administrator of a system that includes the power distribution network estimation device 1 or the owner of the sensor 300 or the sensor 308 powers the sensor 300 or the sensor 308 .
- the sensor 300 or the sensor 308 acquires information (Internet Protocol (IP) address or the like) used for accessing the power distribution network estimation device 1 , and records the information in the recording unit 304 .
- IP Internet Protocol
- the information of the power distribution network estimation device may be manually set by the administrator, or may be set using setting information broadcasted by the power distribution network estimation device 1 to the sensor 300 or the sensor 308 .
- individual functional units in the sensor 300 or the sensor 308 are powered, and the sensor 300 or the sensor 308 is shifted to a state for waiting for a request from the power distribution network estimation device 1 .
- the power distribution network estimation device 1 will be described.
- the power distribution network estimation device 1 is powered on by the administrator of the system or the like.
- the power distribution network estimation device 1 acquires information (IP address or the like) used for accessing the sensor 300 or the sensor 308 that is to be a target of monitoring, and records the information in a power distribution network estimation device information database 1104 described later (refer to FIG. 11 ).
- the information used for accessing the information used for accessing the sensor 300 or the sensor 308 may be manually set by the administrator, or information of which the sensor gives notice may be received as the information used for accessing the information used for accessing the sensor 300 or the sensor 308 .
- FIG. 4 is a block diagram illustrating an embodiment of the power distribution network estimation device.
- the power distribution network estimation device 1 illustrated in FIG. 4 includes a communication unit 401 , a system determination unit 402 , a load presence/absence determination unit 403 , an electric power consumption calculation unit 404 , a control unit 405 , a recording unit 406 , and a display unit 407 .
- the communication unit 401 complies with an instruction from the control unit 405 , and transmits to the sensor 300 provided in the power distribution network a measurement start notice including information for the opening and closing of the switch SW 1 and information for voltage measurement.
- the communication unit 401 transmits a measurement start notice to a subsequent sensor 300 , after confirming the reception of a measurement completion notice from the sensor 300 that is currently a target, which corresponds to the measurement start notice transmitted to the sensor that is currently the target, the communication unit 401 transmits the measurement start notice to the subsequent sensor 300 .
- the measurement start notice includes an identifier assigned to each sensor 300 , information for the opening and closing of the switch SW 1 that corresponds to the identifier, and information for voltage measurement. For example, in the case of the power distribution network illustrated in FIG.
- the communication unit 401 when the communication unit 401 receives an instruction for starting measurement from the control unit 405 , first, the communication unit 401 transmits a measurement start notice to a sensor SV 1 . In addition, the communication unit 401 confirms the reception of a measurement completion notice from the sensor SV 1 , and transmits a measurement start notice to a sensor SV 2 . In this way, the communication unit 401 transmits measurement start notices to sensors SV 1 to SV 3 , and receives measurement completion notices from the sensors SV 1 to SV 3 .
- the communication unit 401 outputs information such as voltage values, measured by the sensor 300 provided in the power distribution network when the switch SW 1 is opened and closed, respectively, or the like to the system determination unit 402 , the load presence/absence determination unit 403 , and the control unit 405 (the communication unit 401 may output the information to the electric power consumption calculation unit 404 ).
- the communication unit 401 may use Internet Protocol (IP) communication such as a local area network (LAN), wireless LAN, power line communications (PLC), or the like.
- IP Internet Protocol
- LAN local area network
- PLC power line communications
- the communication unit 401 may use serial communication such as Recommended Standard 232C (RS232C) or the like, or may use Near Field Communication that uses infrared light, Bluetooth (registered trademark), ZigBee (registered trademark), or the like.
- the system determination unit 402 estimates a system in the power distribution network, using a voltage value measured by a sensor provided for a load in the power distribution network.
- the load presence/absence determination unit 403 estimates the state of the load in the power distribution network, using the estimation result of the system obtained by the system determination unit 402 and the voltage value measured by the sensor provided for the load in the power distribution network.
- the electric power consumption calculation unit 404 estimates the state of the electric power consumption of the power distribution network, using the estimation result of the system, the estimation result of the state of the load, and the voltage value measured by the sensor provided for the load in the power distribution network.
- the control unit 405 controls the communication unit 401 , the system determination unit 402 , the load presence/absence determination unit 403 , the electric power consumption calculation unit 404 , the recording unit 406 , the display unit 407 , and the like.
- the control unit 405 controls the individual units using a central processing unit (CPU) or a programmable device.
- a program, a table, data, and the like are recorded in the recording unit 406 .
- the recording unit 406 is a memory such as a read only memory (ROM), a random access memory (RAM), a hard disk, or the like.
- the recording unit 406 may record therein data such as a parameter value, a variable value, and the like or may be used as a work area.
- database and the like are recorded in the recording unit 406 .
- the details of the system determination unit 402 , the load presence/absence determination unit 403 , the electric power consumption calculation unit 404 , the control unit 405 , and the recording unit 406 will be described later.
- the display unit 407 is a display or the like, and displays information used for an operation on the screen of the display, in response to an instruction from the control unit 405 .
- the information used for the operation or the like is information used when a user performs the operation of the power distribution network estimation device 1 , a setting at the time of measurement, an initial setting, and the like.
- a signal (operation signal) that indicates information used for an operation or the like input through an arbitrary input not illustrated in FIG. 4 is sent to the display unit 407 through the control unit 405 .
- the display unit 407 is used when the processing results of the system determination unit 402 , the load presence/absence determination unit 403 , and the electric power consumption calculation unit 404 are displayed on the screen of the display.
- the information displayed on the display unit 407 is data acquired from a database recorded in the recording unit 406 or the like.
- FIGS. 5 and 6 are diagrams illustrating examples of the system determination.
- FIG. 5 is a diagram illustrating a sensor group in which a positional relationship between sensors is unknown in the power distribution network.
- FIG. 6 is a diagram illustrating a system to which sensors belong.
- a system determination unit 402 (not illustrated) in the power distribution network estimation device 1 arbitrarily selects a sensor to be a reference from among the sensor group in which the positions of the sensors are unspecified.
- the sensor to be a reference is called a reference sensor.
- a sensor SV 2 is selected as the reference sensor.
- the system determination unit 402 selects one sensor other than the reference sensor.
- a sensor SV 3 in FIG. 5 is selected.
- the system determination unit 402 instructs two sensors to measure voltage values produced when the switches SW 1 are closed, and instructs one sensor that has a higher measured voltage value to open the switch SW 1 (a load is separated from the power distribution network).
- the reason why one of the two sensors, which has the higher measured voltage value, is located on an upstream side is because a voltage value measured by a sensor connected to the upstream side of a target system is higher than a voltage value measured by a sensor connected to the downstream side of the system if the two sensors belong to the same system.
- the reason why the sensor located on the upstream side is selected is because it is assumed that the change of the amount of a current flowing into a target load is greater when the switch SW 1 in the sensor located on the upstream side is opened and closed.
- the power source of the load is in a state in which the on-off operation thereof can be performed (a state in which no problem occurs in the on-off operation thereof).
- the system determination unit 402 instructs the two sensors to measure voltage values. In addition, using the voltage values measured by the sensors, the system determination unit 402 determines whether the two sensors belong to the same system or systems different from each other. For example, in the case illustrated in FIG. 6 , it turns out that the sensor SV 2 is located on the upstream side, and the sensor SV 3 is located on the downstream side.
- a method will be described in which it is determined whether the two sensors belong to the same system or systems different from each other.
- FIG. 7 it may be assumed that a voltage value measured when the switch SW 1 in the sensor SV 2 installed on the upstream side is closed is V 10 , and a voltage value measured when the switch SW 1 in the sensor SV 2 is opened is V 11 .
- a voltage value measured when the switch SW 1 in the sensor SV 3 installed on the downstream side is closed is V 20 , and a voltage value measured when the switch SW 1 in the sensor SV 3 is opened is V 21 .
- a voltage value measured when the switch SW 1 in the sensor SV 1 is opened is V 31 .
- V 10 /V 30 ⁇ V 11 /V 31 is satisfied between the measured voltage value V 10 and the measured voltage value V 30 .
- V 10 /V 11 ⁇ V 30 /V 31 it may be determined that the two sensors belong to systems different from each other, respectively.
- resistances Ra, Rb, Rc, and Rd indicate loads to which no sensor is connected.
- Resistances r 0 , r 1 , r 2 , r 3 , and r 4 indicate the conductor resistances of circuit wiring.
- a resistance value R 1 is the resistance value of the sensor SV 2 that has a higher measured voltage value
- a resistance value R 2 is the resistance value of the sensor SV 3 when the sensor SV 3 belongs to the same system.
- the resistance value R 2 is the resistance value of the sensor SV 1 .
- the equivalent circuit of the power distribution network that includes the two sensors turns out to be a circuit illustrated in FIG. 8 .
- the voltage value V 10 of the sensor SV 2 and the voltage value V 20 of the sensor SV 3 are expressed as follows.
- the equivalent circuit of the power distribution network that includes the two sensors turns out to be a circuit illustrated in FIG. 9 .
- the voltage value V 10 of the sensor SV 2 and the voltage value V 30 of the sensor SV 1 are expressed as follows.
- V ⁇ ⁇ 10 V ⁇ ⁇ 30 ( r ⁇ ⁇ 1 ⁇ r ⁇ ⁇ 2 Rc + r ⁇ ⁇ 1 + r ⁇ ⁇ 2 ) ⁇ ( 1 R ⁇ ⁇ 2 + 1 Rd ) + r ⁇ ⁇ 1 Rc + 1 ( r ⁇ ⁇ 3 ⁇ r ⁇ ⁇ 4 Rb + r ⁇ ⁇ 3 + r ⁇ ⁇ 4 ) ⁇ ( 1 R ⁇ ⁇ 1 + 1 Ra ) + r ⁇ ⁇ 3 Rb + 1 [ Expression ⁇ ⁇ 4 ]
- a positional relationship in the same system or in different systems
- the measurement error of the voltage measurement unit 301 it is desirable for the measurement error of the voltage measurement unit 301 to be less than or equal to 0.25%.
- the positional relationship between the two sensors can be estimated by averaging a plurality of measurement results.
- the power distribution network estimation device 1 estimates the positional relationship between the sensors, with respect to the cause of the change of a voltage value, a distinction is made whether the voltage value is changed owing to the change of a resistance value caused by a load to which a sensor is connected, or the amount of electric power consumption is changed owing to a load to which no sensor is connected.
- the load to which no sensor is connected is an air conditioner
- the amount of a current flowing into a load to which a sensor is connected is changed owing to the power-on of the air conditioner.
- a current I 1 flows into the sensor SV 2 .
- the load Rb when the load Rb operates, the current I 1 and a current I 2 flow into the sensor SV 2 , and hence a voltage value measured by the sensor SV 2 is affected. Namely, in response to the operating condition of a load to which no sensor is connected, the above-mentioned processing operation in which it is determined whether sensors belong to the same system or the systems different from each other turns out to be affected. Therefore, the operating condition of a load is considered. In this regard, however, when a load to which no sensor is connected is not frequently turned on and off, the operating condition of a load may not be considered.
- FIG. 11 is a diagram illustrating an example of the control unit 303 in a sensor.
- the control unit 303 includes a voltage value acquisition unit 1101 , a resistance value change unit 1102 , and a measurement synchronization unit 1103 .
- the voltage value acquisition unit 1101 acquires the voltage value of a position to which a sensor is connected, on the basis of a request from the power distribution network estimation device 1 , and sends back the measurement result to the power distribution network estimation device 1 through the communication unit 302 .
- An operation performed in the voltage value acquisition unit 1101 will be described with reference to FIG. 12 .
- FIG. 12 is a flowchart illustrating an example of the operation performed in the voltage value acquisition unit 1101 .
- the voltage value acquisition unit 1101 receives from the power distribution network estimation device 1 a measurement request (voltage value acquisition request) for measuring the voltage value of a position to which a sensor is connected.
- the voltage value acquisition request includes information of a time and date, at which the power distribution network estimation device 1 measures a voltage value, and a time period, during which the power distribution network estimation device 1 measures a voltage value.
- the voltage value acquisition unit 1101 measures a voltage value at the requested time and date and during the requested time period, and adds a time stamp to the measurement result to record the measurement result in a voltage value information database 1105 (voltage value information DB).
- a voltage value information database 1105 voltage value information database 1105
- the voltage value acquisition unit 1101 may constantly measure and record a voltage value in the voltage value information database 1105 .
- the voltage value information database 1105 will be described later.
- the voltage value acquisition unit 1101 acquires from the voltage value information database 1105 the measurement result for the time and date and the time period, requested from the power distribution network estimation device 1 , and sends back the measurement result to the power distribution network estimation device 1 .
- a processing operation in which a voltage value at the specified time and date is measured is described in the flowchart mentioned above, two times and dates may be specified and a ratio between voltage values measured at individual times and dates may be calculated and sent back to the power distribution network estimation device 1 .
- the resistance value change unit 1102 separates a load from the power distribution network, and performs a processing operation for changing a voltage value to be measured by a sensor.
- FIG. 13 is a flowchart illustrating an example of an operation performed in the resistance value change unit 1102 .
- the resistance value change unit 1102 receives from the power distribution network estimation device 1 a change request (resistance change request) for changing the resistance value of the sensor.
- the resistance change request includes information of a change method for a resistance value and information of a time and date, at which the resistance value is changed, and a time period, during which the resistance value is changed.
- the change method indicated in the resistance change request is a method for opening the switch SW 1 in the sensor 300 and separating a load from the power distribution network, a method for changing the resistance value of the variable resistance RV 1 in the sensor 308 , or the like.
- the resistance value change unit 1102 changes the resistance value at the requested time and date and during the requested time period, using the requested method, and records the state of the resistance value in the load information database 1106 (load information DB).
- load information database 1106 The load information database 1106 will be described later.
- the measurement synchronization unit 1103 assists to extract the change of a voltage value due to the change of a resistance value in the sensor.
- the measurement synchronization unit 1103 causes a clock to be correctly synchronized.
- FIG. 14 is a flowchart illustrating an example of an operation performed in the measurement synchronization unit 1103 .
- the measurement synchronization unit 1103 receives a synchronization request for a time and date from the power distribution network estimation device 1 .
- the measurement synchronization unit 1103 synchronizes the clock thereof with a correct time and date, using a global positioning system (GPS) or the like.
- GPS global positioning system
- the processing operation performed in the measurement synchronization unit 1103 in the sensor may not be performed.
- FIGS. 15A to 15C are diagrams illustrating examples of the structures of the power distribution network estimation device information database 1104 , the voltage value information database 1105 , and the load information database 1106 , recorded in the recording unit 304 in the sensor 300 .
- Information used for communicating with the power distribution network estimation device 1 , or the like is recorded in the power distribution network estimation device information database 1104 , and in the example illustrated in FIG. 15A , as an example of information used for communication, “A.B.C.D0” is recorded in “communication interface information”.
- a voltage value measured by the sensor and a time and data at which the sensor measured the voltage value are recorded in the voltage value information database 1105 .
- FIG. 15A A voltage value measured by the sensor and a time and data at which the sensor measured the voltage value
- FIG. 16 is a diagram illustrating examples of the system determination unit 402 and the recording unit 406 in the power distribution network estimation device 1 .
- the system determination unit 402 includes a voltage measurement request unit 1601 , a resistance change request unit 1602 , a measurement synchronization request unit 1603 , an estimation unit 1604 , and a determination unit 1605 .
- the voltage measurement request unit 1601 instructs each sensor to measure a voltage value, and acquires the measurement result from each sensor. A processing operation performed when the voltage measurement request unit 1601 receives a measurement request for a voltage value will be described on the basis of a flowchart illustrated in FIG. 17 .
- the voltage measurement request unit 1601 receives a measurement request for a voltage value, which is to be made to a sensor, from the control unit 405 in the power distribution network estimation device 1 .
- the request includes information relating to the identifier of a sensor that the voltage measurement request unit 1601 requests to measure a voltage value, a time and date, at which the voltage value is to be measured, and a time period, during which the voltage value is to be measured.
- the voltage measurement request unit 1601 searches the sensor information database 1606 (sensor information DB), and acquires information for accessing a sensor to be instructed to measure a voltage value.
- the sensor information database 1606 will be described later.
- the voltage measurement request unit 1601 transmits a measurement request for a voltage value to the sensor the information for access to which is obtained in S 1702 .
- the request includes information of a time and date, at which the voltage value is to be measured, and a time period, during which the voltage value is to be measured.
- the voltage measurement request unit 1601 receives the measurement result of a voltage value from the sensor.
- the voltage measurement request unit 1601 records the measurement result of a voltage value, received from the sensor, in the voltage value information database 1607 (voltage value information DB).
- the voltage value information database 1607 will be described later.
- the resistance change request unit 1602 requests each sensor to change over the switch SW 1 in the sensor or to change the resistance value of the variable resistance RV 1 .
- a processing operation performed in the resistance change request unit 1602 will be described on the basis of a flowchart illustrated in FIG. 18 .
- the resistance change request unit 1602 receives a change request for changing over the switch SW 1 in a sensor or changing the resistance value of the variable resistance RV 1 from the control unit 405 .
- the request includes information relating to the identifier of a sensor that the resistance change request unit 1602 requests to change a resistance value, a method for changing the switch SW 1 or changing the resistance value of the variable resistance RV 1 , a time and date, at which the resistance value is to be changed, and a time period, during which the resistance value is to be changed.
- the resistance change request unit 1602 searches the sensor information database 1606 , and acquires information for accessing a sensor to be instructed to change over the switch SW 1 or to change the resistance value of the variable resistance RV 1 .
- the resistance change request unit 1602 transmits a resistance change request to the sensor the information for access to which is acquired in S 1802 .
- the request includes information relating to a method for changing the switch SW 1 or changing the resistance value of the variable resistance RV 1 , a time and date, at which the resistance value is to be changed, and a time period, during which the resistance value is to be changed.
- the power distribution network estimation device 1 estimates the positional relationship between the sensors, a distinction is made whether the cause of the change of a voltage value measured by the sensor is based on the sensor or the change of the amount of electric power consumption due to a load to which no sensor is connected.
- the measurement synchronization request unit 1603 requests each sensor to assist to extract the change of a voltage value due to the changeover of the switch SW 1 in the sensor or the change of the resistance value of the variable resistance RV.
- a processing operation performed in the measurement synchronization request unit 1603 will be described on the basis of a flowchart illustrated in FIG. 19 .
- the procedure of an operation in which the measurement synchronization request unit 1603 requests a sensor to synchronize a clock to a time will be described.
- the measurement synchronization request unit 1603 receives from the control unit 405 a request for synchronizing a time and date of a clock or the like included in the measurement synchronization unit 1103 in the sensor.
- the request includes the identifier of the sensor to be requested to synchronize a time and date.
- the measurement synchronization request unit 1603 searches the sensor information database 1606 , and acquires information for accessing two sensors to be instructed to synchronize clocks thereof to a time.
- the measurement synchronization request unit 1603 transmits requests for synchronizing the clocks to the sensors the information for access to which is acquired in S 1902 .
- a request processing operation will be described that is performed so that the measurement synchronization request unit 1603 changes over the switch SW 1 or changes the resistance value of the variable resistance RV 1 , changes voltage values with a specified interval, and extracts voltage values that change with substantially the same interval from among the measurement results of voltage values.
- the voltage measurement request unit 1601 and the resistance change request unit 1602 output no request, and the switch SW 1 is changed over or the resistance value of the variable resistance RV 1 is changed, through the measurement synchronization request unit 1603 .
- the measurement synchronization request unit 1603 receives a request for extracting the change of a voltage value, which is to be made to a sensor, from the control unit 405 in the power distribution network estimation device 1 .
- the request includes information of the identifier of a sensor to be the target of the request.
- the measurement synchronization request unit 1603 makes a request for acquiring a voltage value, which is to be made to a sensor, to the voltage measurement request unit 1601 .
- the request includes information of a sensor that measures the voltage value and information of a measurement period for the voltage value. After that, a voltage value during the measurement period, acquired from the target sensor, is recorded in the voltage value information database 1607 in the power distribution network estimation device 1 .
- the measurement synchronization request unit 1603 makes a request to the resistance change request unit 1602 so that a sensor having a higher measured voltage value (a sensor guessed to be located on the upstream side) from among sensors is caused to periodically change over the switch SW 1 or periodically change the resistance value of the variable resistance RV 1 .
- the request includes information relating to the identifier of the target sensor, an interval during which the switch SW 1 is changed over or the resistance value of the variable resistance RV 1 is changed, and a time period during which a voltage value is to be periodically changed.
- the measurement synchronization request unit 1603 extracts a voltage value that changes with substantially the same interval as the interval during which the switch SW 1 in the sensor is changed over or the resistance value of the variable resistance RV 1 in the sensor is changed.
- the determination unit 1605 will be described.
- FIG. 20 is a flowchart illustrating an example of an operation in which a positional relationship between two sensors is determined, by comparing ratios between voltage values measured by the two sensors before and after the switch SW 1 in the sensor is changed over or the resistance value of the variable resistance RV 1 in the sensor is changed.
- the determination unit 1605 receives a request for determining the positional relationship between the two sensors from the estimation unit 1604 .
- the request includes the identifiers of the two sensors to be determination targets.
- the determination unit 1605 requests the measurement synchronization request unit 1603 to synchronize times and dates of clocks in the two sensors.
- the determination unit 1605 requests the voltage measurement request unit 1601 to acquire voltage values V 1 and V 2 at a current time from the two sensors, and records the measurement results in the determination criterion information database 1609 (determination criterion information DB).
- a case in which the sensor 300 is used corresponds to a state in which the switch SW 1 is opened.
- a case in which the sensor 308 is used corresponds to a state in which the switch SW 1 is opened, and the resistance value of the variable resistance RV 1 is set to a high resistance value.
- the measurement result of a voltage value may be acquired by searching the voltage value information database 1607 , or may be directly acquired from the voltage measurement request unit 1601 .
- the determination criterion information database 1609 will be described later.
- the determination unit 1605 request the resistance change request unit 1602 to close the switch SW 1 of the sensor 300 that has a higher measured voltage value (the sensor guessed to be located on the upstream side).
- the resistance value of the variable resistance RV 1 is set to a lower resistance value.
- the determination unit 1605 request the voltage measurement request unit 1601 to acquire, from the two sensors, voltage values V 1 ′ and V 2 ′ at a time and data at which the processing operation in S 2004 has finished. In addition, the determination unit 1605 acquires and records the measurement results in the determination criterion information database 1609 .
- the measurement results of voltage values may be acquired by searching the voltage value information database 1607 , or may be directly acquired from the voltage measurement request unit 1601 .
- the determination unit 1605 reads the voltage values measured by the two sensors from the determination criterion information database 1609 , and calculates ratios between the voltage values measured by the two sensors before and after the resistance value of the sensor is changed. For example, when the sensor 300 is used, a ratio V 1 /V 2 when the switch SW 1 is opened and a ratio V 1 ′/V 2 ′ when the switch SW 1 is closed are calculated.
- the determination unit 1605 determines whether or not the ratios between the voltage values exist within a range preliminarily set in the recording unit 406 before and after the switch SW 1 in the sensors is changed over or the resistance value of the variable resistance RV 1 in the sensor is changed.
- the processing operation proceeds to S 2008 (Yes)
- the ratios between the voltage values are out of the range, the processing operation proceeds to S 2009 (No).
- the determination unit 1605 determines that the two sensors are connected to the same system, and outputs the determination result to the estimation unit 1604 . In addition, in order to notify a user that the two sensors are connected to the same system, the determination unit 1605 outputs the determination result to the display unit 407 .
- the determination unit 1605 determines that the two sensors are connected to systems different from each other, respectively, and outputs the determination result to the estimation unit 1604 . In addition, in order to notify a user that the two sensors are connected to systems different from each other, respectively, the determination unit 1605 outputs the determination result to the display unit 407 .
- the determination unit 1605 requests the resistance change request unit 1602 to restore to an original state the changeover of the switch SW 1 or the resistance value of the variable resistance RV 1 in the sensor that has a higher measured voltage value.
- FIG. 21 a processing operation will be described in which individual sensors calculate ratios between the voltage values before and after the switch SW 1 in the sensor is changed over or the resistance value of the variable resistance RV 1 in the sensor is changed, and a positional relationship between the sensors is determined by comparing the ratios with each other with respect to the two sensors.
- the determination criterion information database 1609 may not be used.
- the determination unit 1605 receives from the estimation unit 1604 a request for determining a positional relationship between two sensors.
- the request includes the identifiers of the two sensors to be determination targets.
- the determination unit 1605 requests the measurement synchronization request unit 1603 to synchronize times and dates of clocks in the two sensors.
- the determination unit 1605 requests the resistance change request unit 1602 to restore to an original state the changeover of the switch SW 1 or the resistance value of the variable resistance RV 1 in the sensor that has a higher measured voltage value.
- the determination unit 1605 requests the voltage measurement request unit 1601 to cause the two sensors to calculate and send back the ratios between the voltage values before and after the resistance value of the sensor is changed, and acquires a calculation result.
- the determination unit 1605 determines whether or not the ratios between the voltage values, acquired from the two sensors, exist within a specified range. When the ratios between the voltage values exist within the range, the processing operation proceeds to S 2106 , and when the ratios between the voltage values are out of the range, the processing operation proceeds to S 2107 .
- the determination unit 1605 determines that the two sensors are connected to the same system, and outputs the determination result to the estimation unit 1604 . In addition, in order to notify a user that the two sensors are connected to the same system, the determination unit 1605 outputs the determination result to the display unit 407 .
- the determination unit 1605 determines that the two sensors are connected to systems different from each other, respectively, and outputs the determination result to the estimation unit 1604 . In addition, in order to notify a user that the two sensors are connected to systems different from each other, respectively, the determination unit 1605 outputs the determination result to the display unit 407 .
- the determination unit 1605 requests the resistance change request unit 1602 to restore to an original state a sensor that has a higher measured voltage value. A processing operation performed in the estimation unit 1604 will be described.
- a processing operation will be described in which a positional relationship between all sensors in the power distribution network is estimated by recursively performing a processing operation in which a sensor connected to the same system is extracted from among a group of sensors the positions of which are unidentified.
- the estimation unit 1604 receives an instruction for position estimation from a user who monitors the power distribution network or the like, through an input device and the control unit 405 .
- the estimation unit 1604 adds all sensors to be position estimation targets to an item for an unspecified position, illustrated in FIG. 23C , in the system information database 1608 (system information DB).
- system information database 1608 system information database
- the estimation unit 1604 selects a sensor that has the lowest voltage value from the item for an unspecified position in the system information database 1608 , and sets the sensor as a reference sensor.
- the voltage measurement request unit 1601 may be requested to acquire the voltage values of all sensors.
- the estimation unit 1604 adds to the system information database 1608 an item for recording a sensor connected to the same system to which the reference sensor is connected (“information of sensor that belongs to system” in FIG. 23C ).
- the estimation unit 1604 instructs the determination unit 1605 to determine a positional relationship between a sensor, registered in the item for an unspecified position in the system information database 1608 , and the reference sensor.
- a sensor determined by the estimation unit 1604 to be connected to the same system to which the reference sensor is connected is deleted from the item for an unspecified position in the system information database 1608 .
- sensors determined by the estimation unit 1604 to be connected to the same system to which the reference sensor is connected are sorted in descending order of the voltage values thereof, and are added to the item created in S 2204 . Namely, the sensors are ranked in order of upstream positions (positions near a power source) in the same system, at which the sensors are located.
- the voltage measurement request unit 1601 may be requested to acquire the voltage value of a sensor connected to the same system to which the reference sensor is connected.
- the estimation unit 1604 determines whether or not a sensor remains in the item for an unspecified position in the system information database 1608 . When a sensor remains (Yes), the processing operation proceeds to S 2203 , and when no sensor remains (No), the processing operation of the estimation unit 1604 is terminated.
- FIGS. 23A to 23D are diagrams illustrating examples of the structures of the sensor information database 1606 , the voltage value information database 1607 , the system information database 1608 , and the determination criterion information database 1609 , recorded in the recording unit 406 .
- the sensor information database 1606 illustrated in FIG. 23A records therein “sensor ID” used for recording an identifier of a sensor and information “communication interface information” used for communicating with a sensor.
- “Sensor — 01”, “Sensor — 02” . . . are recorded in the “sensor ID”.
- system ID that is an identifier for distinguishing systems included in the power distribution network and “information of sensor that belongs to system” that is information of a sensor connected to each system are recorded.
- “Line — 01”, . . . are recorded in the “system ID” and “Sensor — 01, Sensor — 02 . . . ” are recorded in the “information of sensor that belongs to system”.
- “sensor ID” and “load” that is information for indicating the changeover state of the switch SW 1 in a sensor and the state of the change of the resistance value of the variable resistance RV 1 are recorded.
- a voltage value measured in a state corresponding to the “load” is recorded in the “voltage value [V]”.
- “Sensor — 01”, “Sensor — 02” . . . are recorded in the “sensor ID”.
- the measurement synchronization request unit 1603 performs a processing operation in place of Operations S 2002 to S 2005 in FIG. 20 .
- the measurement synchronization request unit 1603 receives an instruction for determining a positional relationship between two sensors from the estimation unit 1604 .
- the instruction includes the identifiers of the two sensors to be determination targets.
- the measurement synchronization request unit 1603 instructs a sensor 1 located on the upstream side about a changeover period in which the switch SW 1 in the sensor 1 is changed over or the resistance value of the variable resistance RV 1 is changed (period changeover notice).
- the changeover period is specified as 10 seconds or the like. However, the changeover period is not limited to 10 seconds.
- the measurement synchronization request unit 1603 notifies a sensor 2 located on the downstream side of the changeover period of the sensor 1 .
- the measurement synchronization request unit 1603 issues an instruction to the sensor 1 to change over the switch SW 1 or change the resistance value of the variable resistance RV 1 .
- the measurement synchronization request unit 1603 notifies the sensor 1 that the changeover instruction is transmitted.
- the measurement synchronization unit 1103 in the sensor 1 measures voltage values before and after the changeover operation, and records the voltage values in the voltage value information database 1105 .
- the measurement synchronization unit 1103 in the sensor 2 measures voltage values before and after the changeover operation, and records the voltage values in the voltage value information database 1105 .
- the measurement synchronization request unit 1603 waits for a specified period (for example, 5 minutes), and instructs the sensor 1 to halt the changeover operation, at the time of (8).
- the sensor 1 extracts the periodic change of a voltage from the voltage value information database 1105 , and the sensor 1 notifies the measurement synchronization request unit 1603 of a voltage value (V 10 ) before the changeover operation and a voltage value (V 11 ) after the changeover operation, at the time of (10).
- the measurement synchronization request unit 1603 notifies the sensor 2 of the halt of the changeover operation.
- the sensor 2 extracts the periodic change of a voltage from the voltage value information database 1105 , and the sensor 2 notifies the measurement synchronization request unit 1603 of a voltage value (V 20 ) before the changeover operation and a voltage value (V 21 ) after the changeover operation, at the time of (13).
- the system of a load connected to a sensor connected to the power distribution network can be determined using a voltage value measured by the sensor.
- the sensor can measure a voltage value at a specified time and date at the time of system determination, the voltage value can be measured, away from a time zone in which a load that is not connected to the sensor operates. Therefore, the system can be correctly determined.
- FIG. 25A is an equivalent circuit illustrating an embodiment of loads connected to a same system in a power distribution network.
- the calculation of total electric power consumption Pj in a range 2501 that is located downstream of an electric power-supply end j and is surrounded with a dashed line is performed as follows.
- the ⁇ value and the ⁇ value are constants obtained from parameters located downstream of the electric power-supply end i
- GLj is the conductance of a load connected to the electric power-supply end j
- G′ is the combined conductance of loads located downstream of the electric power-supply end j, and it is indicated that G′ linearly behaves for GLj in Expression 5. Accordingly, when GLj is measured at more than one point, it turns out that the measurement results exist on a straight line (dashed line) as illustrated in FIG. 26 .
- FIG. 25B is an equivalent circuit illustrating an embodiment of loads connected to a same system circuit in the power distribution network. As illustrated in FIG. 25B , when there are a plurality of loads between the electric power-supply end i and an electric power-supply end z, current values between individual electric power-supply ends can be expressed using a current conservation equation, on the basis of Expression 6.
- O(x n ) indicates terms higher than or equal to n-order term with respect to an arbitrary variable x, and is negligible when x ⁇ 1.
- the ⁇ value is estimated by measuring the effect of the load between the electric power-supply end i and the electric power-supply end z.
- the variation portion ⁇ (Vi/Vj) of (Vi/Vj) due to the power-on and power-off of the load between the electric power-supply ends is calculated, the variation portion ⁇ (Vi/Vj) is expressed as Expression 9.
- “ON” in Expression 9 indicates the power-on, and “OFF in Expression 9 indicates the power-off.
- the ⁇ value can be estimated on the basis of the voltage ratio fluctuation ⁇ (Vi/Vj) obtained when the resistance value of the load between the electric power-supply ends is changed.
- FIG. 27 is a diagram for explaining a method used for estimating the presence or absence of a load between the electric power-supply ends to be measured. As illustrated in FIG. 27 , by measuring voltage values at desired electric power-supply ends i and j and an electric power-supply end k located downstream of the electric power-supply end j, which are positioned on an electric wiring line, voltage information can be acquired. In addition, using the voltage ratio fluctuation thereof, it is determined whether or not there is a load between the desired electric power-supply ends i and j.
- the resistance value RLj of the load connected to the electric power-supply end j is changed, and then the individual voltage values of the electric power-supply ends i and j are measured, it can be determined, using the voltage measurement result, whether or not there is a load between the electric power-supply ends i and j.
- the total electric power consumption Pj on the downstream side of the electric power-supply end j can also be directly calculated on the basis of Expression 11, using, as the voltage measurement result, the voltage values (Vi, Vj) of the electric power-supply ends i and j before the resistance value RLj is changed and the voltage values (Vi′, Vj′) of the electric power-supply ends i and j after the resistance value RLj is changed.
- each of GLj and G′Lj is the value of conductance connected to the load of electric power-supply end j
- Gij is the conductance of a conductive wire between the electric power-supply ends i and j.
- the ⁇ value may be estimated by measuring the effect of the load between the electric power-supply ends. If the resistance value of a load (2) between the electric power-supply ends is variable or the effect thereof can be estimated, the ⁇ value can be expressed with Expression 12 as follows. ⁇ ( Vi/Vj ) [Expression 10]
- the right side of Expression 12 corresponds to the variation portion of (Vi/Vj) due to the power-on and power-off of the load (2).
- the ⁇ value can be calculated using the above-mentioned method.
- an electric power-supply end may be changed, the voltage of which is to be measured, to the position of the load (2) and try to perform voltage measurement again.
- it is difficult to even measure the load (2) only an approximate value can be obtained.
- FIG. 28 is an equivalent circuit illustrating embodiments of sensors and loads connected to a same system in the power distribution network.
- Sensor SVi, SVj, and SVk illustrated in FIG. 28 are substantially the same sensors as the sensor 300 or 308 , and loads Fi, Fj, and Fk are connected to the sensors 300 or 308 as illustrated in FIGS. 3A and 3B .
- the load presence/absence determination unit 403 in FIG. 4 communicates with the sensors SVi, SVj, and SVk through the communication unit 401 , and acquires voltage values measured by the sensors.
- FIG. 29 is a diagram illustrating embodiments of a load presence/absence determination unit and an electric power consumption calculation unit.
- the load presence/absence determination unit 403 includes a voltage ratio calculation unit 2901 , a comparison unit 2902 , and a presence/absence determination unit 2903 .
- the voltage ratio calculation unit 2901 When a load presence/absence determination operation is performed, the voltage ratio calculation unit 2901 notifies the voltage measurement request unit 2905 , the resistance change request unit 2906 , and the measurement synchronization request unit 2907 of individual instructions, in order to acquire a voltage value.
- the voltage ratio calculation unit 2901 acquire voltage values from sensors connected to three electric power-supply ends connected to the same system in the power distribution network.
- acquired voltage values are the voltage value of a first electric power-supply end, the voltage value of a second electric power-supply end, and the voltage value of a third electric power-supply end, ranked in descending order, and then a first ratio between the voltage values of the first and second electric power-supply ends and a second ratio between the voltage values of the second and third electric power-supply ends are calculated.
- the comparison unit 2902 calculates a difference between the first ratio and the second ratio. When the difference between the ratios is out of a specified range, the presence/absence determination unit 2903 determines that there is a load between the first electric power-supply end and the second electric power-supply end.
- the measurement synchronization request unit 2907 synchronizes the measurement of sensors in substantially the same way as the measurement synchronization request unit 1603 in FIG. 16 .
- the functions of the voltage measurement request unit 2905 , the resistance change request unit 2906 , and the measurement synchronization request unit 2907 may be included in the voltage measurement request unit 1601 , the resistance change request unit 1602 , and the measurement synchronization request unit 1603 , respectively. In such a case as described above, the voltage measurement request unit 2905 , the resistance change request unit 2906 , and the measurement synchronization request unit 2907 may be deleted from the load presence/absence determination unit 403 .
- FIGS. 30 and 31 are diagrams illustrating examples of operations performed in load presence/absence determination and electric power consumption calculation.
- the load presence/absence determination unit 403 acquires a plurality of individual voltage values in chronological order from each of the sensors 300 or the sensors 308 , connected to three loads that are targets. For example, when voltage values at electric power-supply ends i, j, and k illustrated in FIG. 28 are measured, the load presence/absence determination unit 403 sends an instruct for acquiring a voltage value to the voltage measurement request unit 2905 , and then the voltage measurement request unit 2905 notifies, through the communication unit 401 , the sensors SVi, SVj, and SVk of instructs to acquire voltage values.
- the voltage ratio calculation unit 2901 acquires and records the voltage values of the electric power-supply ends i, j, and k in the voltage ratio information database 2904 in the recording unit 406 .
- times and dates at which the voltage values are measured are recorded in “time and date”
- voltage values corresponding to the times and dates of the measurement are recorded in “voltage value Vi”, “voltage value Vj”, and “voltage value Vk”, respectively.
- FIG. 32A . . .
- the voltage ratio calculation unit 2901 calculates the ratios between voltage values using three voltage values sequentially acquired. In addition, it is determined whether or not there is no difference between the ratios. In addition, when no difference between the ratios is detected (Yes), the processing operation proceeds to S 3003 , and when a difference between the ratios is detected (No), the processing operation proceeds to S 3007 . For example, when the voltage values at the electric power-supply ends i, j, and k illustrated in FIG. 28 are measured, the voltage ratio calculation unit 2901 calculates a voltage ratio Vj/Vk and a voltage ratio Vi/Vj using the voltage values Vi, Vj, and Vk of the electric power-supply ends i, j, and k.
- the voltage values Vi, Vj, and Vk have a relationship Vi>Vj>Vk, and whether each of the electric power-supply ends i, j, and k is located on the upstream side or the downstream side is determined on the basis of the levels of the voltage values at the electric power-supply ends (outlets or the like) as described above.
- the comparison unit 2902 calculates a voltage ratio Vj/Vk and a voltage value ratio Vi/Vj, and records these ratios in the voltage ratio information database 2904 in the recording unit 406 .
- the voltage value ratio Vi/Vj and the voltage ratio Vj/Vk are recorded in “voltage ratio Vi/Vj” and “voltage ratio Vj/Vk”, respectively, with being associated with the times and dates (“time and date” in FIG. 32A ) at which the voltage values are measured.
- . . . “2009/11/20 8:00:01”, “2009/11/20 8:00:02” . . . are recorded in “time and date”.
- In “voltage ratio Vi/Vj”, . . . “1.0123”, “0.9876” . . . are recorded.
- voltage ratio Vj/Vk . . . “1.0234”, “1.0345” . . . are recorded.
- the comparison unit 2902 calculates differences between the values of voltage ratios Vi/Vj within a range in “voltage ratio Vi/Vj”, surrounded with a dashed line, and the values of voltage ratios Vi/Vj in portions other than the range.
- a detection method is not limited to the method described above but any method in which the fluctuation can be detected may be adopted.
- the presence/absence determination unit 2903 determines that there is no load between the electric power-supply ends i and j. Namely, it is determined that the load Fi and the load Fj connected to the electric power-supply ends i and j, respectively, are connected to the electric power-supply ends i and j adjacent to each other, and it is recorded in the voltage ratio information database 2904 in the recording unit 406 that there is no load between the electric power-supply ends i and j. For example, when there is no load, “absence” is recorded with being associated with “voltage ratio Vi/Vj”. In FIG. 32C , while “presence” is noted in “load presence/absence”, “absence” is recorded in the case of S 3003 .
- the electric power consumption calculation unit 404 acquires voltage values produced when the resistance value of the variable resistance RV 1 in the sensor 308 connected to the electric power-supply end j is changed. For example, when two voltage values at the electric power-supply end j illustrated in FIG. 28 are measured, the electric power consumption calculation unit 404 sends an instruction for acquiring the two voltage values to the voltage measurement request unit 2905 , and then causes the voltage measurement request unit 2905 to notify, through the communication unit 401 , the sensor SVj an instruct to acquire the voltage values. In addition, the voltage measurement request unit 2905 notifies, through the communication unit 401 , the sensor SVj of an instruction to acquire the voltage values.
- an instruction for closing the switch SW 1 in the sensor 308 and changing the resistance value of the variable resistance RV 1 is sent to the resistance change request unit 2906 .
- the sensor SVj measures a plurality of voltage values, and transmits information of the measured voltage value to the voltage measurement request unit 2905 .
- the voltage ratio calculation unit 2901 acquires two voltage values of the electric power-supply end j, and records the two voltage values in the voltage ratio information database 2904 in the recording unit 406 . For example, as illustrated in FIG.
- times and dates at which the voltage values are measured are recorded in “time and date”, and a content, which indicates that the switch SW 1 has been changed over or the resistance value of the variable resistance RV 1 has been changed to a reference resistance value and a resistance value other than the reference resistance value, is recorded in “control load” so as to correspond to the time and date.
- a content which indicates that the switch SW 1 has been changed over or the resistance value of the variable resistance RV 1 has been changed to a reference resistance value and a resistance value other than the reference resistance value
- the electric power consumption calculation unit 404 determines a load resistance RLj. Namely, the resistance value of the variable resistance RV 1 is changed to a specified value, and the load resistance RLj is determined.
- the resistance value of a load connected to a sensor is preliminarily known.
- a load may not be connected to a sensor but the variable resistance RV 1 in the sensor may be used.
- the electric power consumption calculation unit 404 notifies the voltage measurement request unit 2905 of an instruction to measure the voltages Vi and Vj. After that, the voltage measurement request unit 2905 notifies, through the communication unit 401 , the sensors SVi and SVj connected to the electric power-supply ends i and j of instructions to measure the voltages Vi and Vj, respectively.
- the sensors SVi and SVj measure the voltage values Vi and Vj at the resistance value of the variable resistance RV 1 determined in S 3401 , and transmit the measured voltage values to the electric power consumption calculation unit 404 .
- the electric power consumption calculation unit 404 records the received voltage values Vi and Vj and an identifier indicating the resistance value of the variable resistance RV 1 in the recording unit 406 with associating the voltage values with the identifier.
- the electric power consumption calculation unit 404 calculates the value of (Vi ⁇ Vj)/Vj using the voltage values Vi and Vj acquired in S 3402 .
- S 3405 it is determined whether or not all data has been measured with respect to the specified resistance value of the variable resistance RV 1 .
- the resistance values of the variable resistance RV 1 are RVa, RVb, and RVc.
- the processing operation proceeds to S 3406 (Yes).
- the voltage values Vi and Vj have not yet been measured for RVa, RVb, and RVc, the processing operation proceeds to S 3401 (No).
- the electric power consumption calculation unit 404 performs a fitting operation on the measurement result, using the linear function (A*GLj+B). While it is desirable to use a least-square method for the fitting operation, the fitting operation is not specifically limited to the least-square method.
- the electric power consumption calculation unit 404 calculates the slope A value and the intercept B value using the fitting result, and records the slope A value and the intercept B in “parameter A” and “parameter B” in the recording unit 406 with associating the slope A value and the intercept B with “time and date” (refer to FIG. 32D ).
- the electric power consumption calculation unit 404 records “presence” in “load presence/absence” illustrated in FIG. 32C .
- the electric power consumption calculation unit 404 identifies a load that exists between the sensors SVi and SVj. For example, for the identification of a load, an identifier corresponding to each load is recorded in the recording unit 406 , and a sign indicating whether or not the load is active is recorded in the recording unit 406 with being associated with the identifier. As an example of the sign, “1” indicates that the load is active, and “0” indicates that the load is not active. In addition, voltage values produced when the load is active are recorded in the recording unit 406 with being associated with the identifier of each load.
- the electric power consumption calculation unit 404 determines whether or not the voltage values produced when the load is active are within a range that ranges from the voltage value of the electric power-supply end i to the voltage value of the electric power-supply end j. In addition, when the voltage values are within the range, the power consumption calculation unit 404 determines that the active load is a load located between the electric power-supply end i and the electric power-supply end j.
- the electric power consumption calculation unit 404 refers to information, which is recorded in the recording unit 406 and indicates whether or not the power-on and power-off associated with the identifier of each load is controllable.
- the processing operation proceeds to S 3010 (Yes).
- the processing operation proceeds to S 3014 (No).
- the information that indicates whether or not the power-on and power-off is controllable is information indicating that a measurement operation can be performed in the nighttime in which a power source can be freely turned on and turned off, the load can be identified as a device the power-on and power-off of which are controllable, or the like.
- the electric power consumption calculation unit 404 acquires the voltage values of the electric power-supply end i and the electric power-supply end j from the sensors SVi and SVj. After that, the ⁇ value is calculated in accordance with Expression 9, and is recorded in the “parameter ⁇ ” in the recording unit 406 (refer to FIG. 32E ).
- the electric power consumption calculation unit 404 calculates the slope A value and the intercept B value in substantially the same way as in S 3004 and S 3005 .
- the electric power consumption calculation unit 404 records information, which indicates whether or not the load located between the electric power-supply end i and the electric power-supply end j is active, and a Vi/Vj value, calculated on the basis of the voltage values Vi and Vj acquired from the sensors, in the recording unit 406 with associating with the information and the Vi/Vj value with a time and date in chronological order.
- the electric power consumption calculation unit 404 acquires the Vi/Vj value obtained when the load located between the electric power-supply end i and the electric power-supply end j is active (power-on) and the Vi/Vj value obtained when the load is not active (power-off). After that, the ⁇ value is calculated in accordance with Expression 9, and is recorded in “parameter ⁇ ” in the recording unit 406 (refer to FIG. 32E ). After that, the processing operation proceeds to S 3011 .
- the electric power consumption calculation unit 404 determines whether or not, at any time (for example, at midnight), the load can be separated once and an electric power meter can be inserted. For example, information indicating whether or not, at any time (for example, at midnight), the load can be separated once and an electric power meter can be inserted is recorded in the recording unit 406 with respect to each load, and the electric power consumption calculation unit 404 refers to the information and performs such determination as described above.
- the processing operation proceeds to S 3020
- electric power is not measurable the processing operation proceeds to S 3017 .
- the electric power consumption calculation unit 404 calculates the approximate value of the electric power consumption Pj.
- the approximate value turns out to be Pj ⁇ Vi*(Vi ⁇ Vj)/A.
- the A value is at the same level as the resistance value of a conductive wire between the electric power-supply end i and the electric power-supply end j
- a value is obtained that corresponds to an expression Pi>Vi*(Vi ⁇ Vj)/A>Pj. Namely, a value is obtained that includes an error as large as up to the electric power consumption of the load located between the electric power-supply end i and the electric power-supply end j.
- processing operation performed in S 3017 and S 3019 calculates the A value in substantially the same way as in 3004 and S 3005 described above.
- the approximate value of the electric power consumption Pj is calculated using the A value, the voltage values Vi and Vj, and the expression Vi*(Vi ⁇ Vj)/A.
- a user moves the sensor SVi connected to the electric power-supply end i to the position of an electric power-supply end to which a load is connected, and notifies the control unit 405 of an instruction to perform the above-mentioned voltage measurement again.
- FIG. 35 is a diagram illustrating an example in which the electric power consumption of a portion subsequent to an electric power-supply end i near a distribution board is measured.
- the sensor 300 or the sensor 308 can be connected to the power distribution network.
- FIG. 36 is a diagram illustrating a circuit configuration when a single-phase two-wire method is used (a sensor 300 is connected). Outlets Ca and Cb indicate electric power-supply ends used for the single-phase two-wire method.
- FIG. 37 is a diagram illustrating a circuit configuration when a single-phase two-wire method and three-terminal outlets are used (a sensor 300 is connected). Outlets Cc and Cd indicate three-terminal electric power-supply ends used for the single-phase two-wire method.
- FIG. 38 is a diagram illustrating a circuit configuration when a single-phase three-wire method is used (a sensor 300 is connected). Outlets Ce and Cf indicate electric power-supply ends used for the single-phase three-wire method. In addition, in FIGS. 36 to 38 , loads Fn are loads connected to sensors.
- FIG. 39 is a diagram illustrating an example of the hardware configuration of a computer that can realize the power distribution network estimation device 1 according to the embodiments described above.
- the hardware 3900 of the computer includes a CPU 3901 , a recording unit 3902 (ROM, RAM, hard disk drive, or the like), a recording medium reader 3903 , an input-output interface 3904 (input-output I/F), a communication interface 3905 (communication I/F), and the like.
- the individual component units are connected to one another through a bus 3906 .
- the CPU 3901 executes individual processing operations such as the system determination operation, the load presence/absence determination operation, the electric power consumption calculation operation, and the like, which are stored in the recording unit 3902 and performed in the power distribution network estimation device 1 described above.
- Program to be executed in the CPU 3901 and data are stored in the recording unit 3902 .
- the recording unit 3902 is used as a work area.
- the recording unit 3902 includes the function of the recording unit 406 , described above.
- the recording medium reader 3903 controls the read and write of data from and to the recording medium 3907 in accordance with the control of the CPU 3901 .
- the CPU 3901 causes the recording medium reader 3903 to store data, written by the control of the recording medium reader 3903 , in the recording medium 3907 , and causes the recording medium reader 3903 to read out data stored in the recording medium 3907 .
- examples of the detachable recording medium 3907 include, as computer-readable recording media, a magnetic recording device, an optical disk, a magneto-optical recording medium, a semiconductor memory, and the like.
- Examples of the magnetic recording device include a hard disk drive (HDD) and the like.
- optical disk examples include a digital versatile disc (DVD), a digital versatile disc random access memory (DVD-RAM), a compact disc read only memory (CD-ROM), a compact disc recordable (CD-R), a compact disc rewritable (CD-RW), and the like.
- magneto-optical recording medium examples include a magneto-optical disk (MO) and the like.
- An input-output device 3908 (for example, a touch panel or the like) is connected to the input-output interface 3904 , and receives and transmits information input by a user to the CPU 3901 through the bus 3906 .
- the input-output device 3908 displays operating information or the like on the screen of a display in response to an instruction from the CPU 3901 .
- the communication interface 3905 is an interface used for establishing LAN connection with another computer, Internet connection, and wireless connection. In addition, the communication interface 3905 is connected to another device, and controls the input and output of data from and to an external device.
- the various kinds of processing functions described above can be realized.
- a program is provided in which the content of processing of functions to be included in the system in such a case is described.
- the above-mentioned processing function is realized on the computer.
- the program in which the content of processing is described can be recorded in the computer-readable recording medium 3907 .
- the recording media 3907 such as DVD, CD-ROM, and the like, in each of which the program is recorded, are sold.
- the program may be stored in a storage device in a server computer, and the program may also be transferred from the server computer to other computers through a network.
- the term “computer-readable recording medium” here includes no transitory propagation signal.
- the computer that executes a program stores in the recording unit 3902 therein a program recorded in the recording medium 3907 or a program transferred from the server computer.
- the computer reads out the program from the recording unit 3902 therein, and executes a processing operation in accordance with the program.
- the computer can also directly read out the program from the recording medium 3907 , and execute a processing operation in accordance with the program.
- every time the program is transferred from the server computer the computer can also sequentially execute a processing operation in accordance with the received program.
- the function of the power distribution network estimation device 1 may also be installed in a server, or installed in the control unit 303 or 312 in a sensor or the like.
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Abstract
Description
(Vi−Vj)/Vj=α(GLj+G′)+β [Expression 5]
Δ(Vi/Vj)=(Vi/Vj)ON−(Vi/Vj)OFF=(αON−αOFF)(GLj+G′)+(βON−βOFF)αON≈αOFF βOFF≈0
Δ(V i /V j)≈β [Expression 9]
Pj=G′Vj 2 =Vj 2(B−β)/A [Expression 10]
β≈Δ(Vi/Vj) [Expression 10]
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US20130082742A1 (en) * | 2011-06-30 | 2013-04-04 | Chengdu Monolithic Power Systems Co., Ltd. | Load detecting circuits and the method thereof |
US20140191574A1 (en) * | 2013-01-09 | 2014-07-10 | Experium Technologies, Llc | Virtual parallel load bank system |
US20150142187A1 (en) * | 2012-07-10 | 2015-05-21 | Hitachi, Ltd. | System and method for controlling power system |
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Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5699051A (en) * | 1996-07-29 | 1997-12-16 | Billig; Richard R. | Load monitoring electrical outlet system |
JPH11308787A (en) | 1998-04-20 | 1999-11-05 | Fuji Electric Co Ltd | Power monitoring system |
US6163144A (en) * | 1998-07-20 | 2000-12-19 | Applied Power Inc. | Electrical circuit tracing apparatus using modulated tracing signal |
US6222358B1 (en) * | 1997-08-25 | 2001-04-24 | Ntc, Inc. | Automatic circuit locator |
JP2002186178A (en) | 2000-12-18 | 2002-06-28 | Neo Techno:Kk | Power supply unit for electrical apparatus |
JP2007052006A (en) | 2005-07-21 | 2007-03-01 | Kyushu Institute Of Technology | Method and system for measuring electric current or power flow |
JP2007052000A (en) | 2005-07-21 | 2007-03-01 | Kyushu Institute Of Technology | Power source tap equipped with means for detecting overcurrent |
US20070139055A1 (en) * | 2006-01-05 | 2007-06-21 | Cockrill Clinton E | Electric Circuit Tracing System |
JP2007199204A (en) | 2006-01-24 | 2007-08-09 | Sharp Corp | Electronic apparatus |
US20080036466A1 (en) * | 2006-08-11 | 2008-02-14 | Raber Monte B | Method for detecting electrical ground faults |
US20080204034A1 (en) * | 2004-03-23 | 2008-08-28 | Pass & Seymour, Inc. | Automated Electrical Wiring Inspection System |
US20090082980A1 (en) * | 2007-09-25 | 2009-03-26 | Square D Company | Virtual branch load management |
US20100145542A1 (en) * | 2007-03-14 | 2010-06-10 | Zonit Structured Solutions, Llc | Smart electrical outlets and associated networks |
US20120062210A1 (en) * | 2010-09-13 | 2012-03-15 | Trilliant Networks, Inc. | Process for Detecting Energy Theft |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0564372A (en) * | 1991-08-29 | 1993-03-12 | Fuji Electric Co Ltd | Specification of higher harmonic source of distribution system |
JP2004219171A (en) * | 2003-01-10 | 2004-08-05 | Matsushita Electric Works Ltd | Information on equipment specifying device and characteristic amount detecting device for load equipment |
JP2004343901A (en) * | 2003-05-16 | 2004-12-02 | Tm T & D Kk | Load amount calculation method for power system, power system monitoring control system, and power system analyzer |
JP2005188937A (en) * | 2003-12-24 | 2005-07-14 | Matsushita Electric Ind Co Ltd | Electric power measuring device |
JP2006184063A (en) * | 2004-12-27 | 2006-07-13 | Matsushita Electric Ind Co Ltd | Power monitoring system |
JP4718943B2 (en) * | 2005-09-15 | 2011-07-06 | 財団法人電力中央研究所 | Distribution system load distribution estimation method, apparatus and program, and voltage estimation method, apparatus and program |
-
2010
- 2010-02-24 JP JP2010038658A patent/JP5501796B2/en not_active Expired - Fee Related
-
2011
- 2011-02-17 US US13/029,392 patent/US8560263B2/en not_active Expired - Fee Related
Patent Citations (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5699051A (en) * | 1996-07-29 | 1997-12-16 | Billig; Richard R. | Load monitoring electrical outlet system |
US6222358B1 (en) * | 1997-08-25 | 2001-04-24 | Ntc, Inc. | Automatic circuit locator |
JPH11308787A (en) | 1998-04-20 | 1999-11-05 | Fuji Electric Co Ltd | Power monitoring system |
US6163144A (en) * | 1998-07-20 | 2000-12-19 | Applied Power Inc. | Electrical circuit tracing apparatus using modulated tracing signal |
JP2002186178A (en) | 2000-12-18 | 2002-06-28 | Neo Techno:Kk | Power supply unit for electrical apparatus |
US20080204034A1 (en) * | 2004-03-23 | 2008-08-28 | Pass & Seymour, Inc. | Automated Electrical Wiring Inspection System |
JP2007052000A (en) | 2005-07-21 | 2007-03-01 | Kyushu Institute Of Technology | Power source tap equipped with means for detecting overcurrent |
JP2007052006A (en) | 2005-07-21 | 2007-03-01 | Kyushu Institute Of Technology | Method and system for measuring electric current or power flow |
US20070139055A1 (en) * | 2006-01-05 | 2007-06-21 | Cockrill Clinton E | Electric Circuit Tracing System |
JP2007199204A (en) | 2006-01-24 | 2007-08-09 | Sharp Corp | Electronic apparatus |
US20080036466A1 (en) * | 2006-08-11 | 2008-02-14 | Raber Monte B | Method for detecting electrical ground faults |
US20100145542A1 (en) * | 2007-03-14 | 2010-06-10 | Zonit Structured Solutions, Llc | Smart electrical outlets and associated networks |
US20090082980A1 (en) * | 2007-09-25 | 2009-03-26 | Square D Company | Virtual branch load management |
US20120062210A1 (en) * | 2010-09-13 | 2012-03-15 | Trilliant Networks, Inc. | Process for Detecting Energy Theft |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130082742A1 (en) * | 2011-06-30 | 2013-04-04 | Chengdu Monolithic Power Systems Co., Ltd. | Load detecting circuits and the method thereof |
US9252766B2 (en) * | 2011-06-30 | 2016-02-02 | Chengdu Monolithic Power Systems Co., Ltd. | Load detecting circuits and the method thereof |
US20150142187A1 (en) * | 2012-07-10 | 2015-05-21 | Hitachi, Ltd. | System and method for controlling power system |
US9774216B2 (en) * | 2012-07-10 | 2017-09-26 | Hitachi, Ltd. | System and method for controlling power system |
US20140191574A1 (en) * | 2013-01-09 | 2014-07-10 | Experium Technologies, Llc | Virtual parallel load bank system |
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